multi: replace statik with go1.16 embed directive

We can now simply use the //go:embed directive to compile everything in
the app/build directory into our root package.

Author: guggero

.gitignore

@@ -4,8 +4,5 @@
 litd-debug
 /lightning-terminal-*
 
-# go code generated by statik
-/statik/statik.go
-
 # MacOS junk
 .DS_Store

Dockerfile

@@ -46,7 +46,6 @@ ENV GO111MODULE on
 RUN apk add --no-cache --update alpine-sdk \
     make \
   && cd /go/src/github.com/lightninglabs/lightning-terminal \
-  && make statik-only \
   && make go-install \
   && make go-install-cli
 

Makefile

@@ -7,13 +7,11 @@ POOL_PKG := github.com/lightninglabs/pool
 LINT_PKG := github.com/golangci/golangci-lint/cmd/golangci-lint
 GOVERALLS_PKG := github.com/mattn/goveralls
 GOACC_PKG := github.com/ory/go-acc
-STATIK_PKG := github.com/rakyll/statik
 
 GO_BIN := ${GOPATH}/bin
 GOVERALLS_BIN := $(GO_BIN)/goveralls
 LINT_BIN := $(GO_BIN)/golangci-lint
 GOACC_BIN := $(GO_BIN)/go-acc
-STATIK_BIN := $(GO_BIN)/statik
 
 COMMIT := $(shell git describe --abbrev=40 --dirty --tags)
 COMMIT_HASH := $(shell git rev-parse HEAD)
@@ -94,25 +92,16 @@ $(GOACC_BIN):
 	@$(call print, "Fetching go-acc")
 	$(DEPGET) $(GOACC_PKG)@$(GOACC_COMMIT)
 
-$(STATIK_BIN):
-	@$(call print, "Fetching statik")
-	$(DEPGET) $(STATIK_PKG)
-
 yarn-install:
 	@$(call print, "Installing app dependencies with yarn")
 	cd app; yarn
 
 # ============
 # INSTALLATION
 # ============
-statik-only: $(STATIK_BIN)
-	@$(call print, "Building statik package.")
-	statik -src=app/build
-
-statik-build: app-build statik-only
 
-build: statik-build go-build
-install: statik-build go-install
+build: app-build go-build
+install: app-build go-install
 
 go-build:
 	@$(call print, "Building lightning-terminal.")
@@ -133,7 +122,7 @@ app-build: yarn-install
 	@$(call print, "Building production app.")
 	cd app; yarn build
 
-release: statik-build
+release: app-build
 	@$(call print, "Creating release of lightning-terminal.")
 	./release.sh build-release "$(VERSION_TAG)" "$(BUILD_SYSTEM)" "$(LND_RELEASE_TAGS)" "$(RELEASE_LDFLAGS)"
 
@@ -214,4 +203,3 @@ clean:
 	@$(call print, "Cleaning source.$(NC)")
 	$(RM) ./lightning-terminal-debug
 	$(RM) coverage.txt
-	$(RM) -r statik

dev.Dockerfile

@@ -27,7 +27,6 @@ ENV GO111MODULE on
 RUN apk add --no-cache --update alpine-sdk \
     make \
   && cd /go/src/github.com/lightninglabs/lightning-terminal \
-  && make statik-only \
   && make go-install \
   && make go-install-cli
 

go.mod

@@ -18,7 +18,6 @@ require (
 	github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f
 	github.com/mwitkow/grpc-proxy v0.0.0-20181017164139-0f1106ef9c76
 	github.com/prometheus/client_golang v1.5.1 // indirect
-	github.com/rakyll/statik v0.1.7
 	github.com/rs/cors v1.7.0 // indirect
 	golang.org/x/crypto v0.0.0-20200709230013-948cd5f35899
 	golang.org/x/net v0.0.0-20200324143707-d3edc9973b7e // indirect

go.sum

@@ -314,8 +314,6 @@ github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsT
 github.com/prometheus/procfs v0.0.8 h1:+fpWZdT24pJBiqJdAwYBjPSk+5YmQzYNPYzQsdzLkt8=
 github.com/prometheus/procfs v0.0.8/go.mod h1:7Qr8sr6344vo1JqZ6HhLceV9o3AJ1Ff+GxbHq6oeK9A=
 github.com/prometheus/tsdb v0.7.1/go.mod h1:qhTCs0VvXwvX/y3TZrWD7rabWM+ijKTux40TwIPHuXU=
-github.com/rakyll/statik v0.1.7 h1:OF3QCZUuyPxuGEP7B4ypUa7sB/iHtqOTDYZXGM8KOdQ=
-github.com/rakyll/statik v0.1.7/go.mod h1:AlZONWzMtEnMs7W4e/1LURLiI49pIMmp6V9Unghqrcc=
 github.com/rogpeppe/fastuuid v1.2.0 h1:Ppwyp6VYCF1nvBTXL3trRso7mXMlRrw9ooo375wvi2s=
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=

statik/doc.go

@@ -3,8 +3,10 @@ package terminal
 import (
 	"context"
 	"crypto/tls"
+	"embed"
 	"errors"
 	"fmt"
+	"io/fs"
 	"net"
 	"net/http"
 	"os"
@@ -29,15 +31,10 @@ import (
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lntest/wait"
 	"github.com/lightningnetwork/lnd/signal"
-	"github.com/rakyll/statik/fs"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 	"gopkg.in/macaroon-bakery.v2/bakery"
-
-	// Import generated go package that contains all static files for the
-	// UI in a compressed format.
-	_ "github.com/lightninglabs/lightning-terminal/statik"
 )
 
 const (
@@ -50,6 +47,19 @@ var (
 	// maxMsgRecvSize is the largest message our REST proxy will receive. We
 	// set this to 200MiB atm.
 	maxMsgRecvSize = grpc.MaxCallRecvMsgSize(1 * 1024 * 1024 * 200)
+
+	// appBuildFS is an in-memory file system that contains all the static
+	// HTML/CSS/JS files of the UI. It is compiled into the binary with the
+	// go 1.16 embed directive below. Because the path is relative to the
+	// root package, all assets will have a path prefix of /app/build/ which
+	// we'll strip by giving a sub directory to the HTTP server.
+	//
+	//go:embed app/build/*
+	appBuildFS embed.FS
+
+	// appFilesDir is the sub directory of the above build directory which
+	// we pass to the HTTP server.
+	appFilesDir = "app/build"
 )
 
 // LightningTerminal is the main grand unified binary instance. Its task is to
@@ -523,14 +533,14 @@ func (g *LightningTerminal) shutdown() error {
 }
 
 // startMainWebServer creates the main web HTTP server that delegates requests
-// between the Statik HTTP server and the RPC proxy. An incoming request will
+// between the embedded HTTP server and the RPC proxy. An incoming request will
 // go through the following chain of components:
 //
 //    Request on port 8443
 //        |
 //        v
 //    +---+----------------------+ other  +----------------+
-//    | Main web HTTP server     +------->+ Statik HTTP    |
+//    | Main web HTTP server     +------->+ Embedded HTTP  |
 //    +---+----------------------+        +----------------+
 //        |
 //        v any RPC or REST call
@@ -566,12 +576,15 @@ func (g *LightningTerminal) shutdown() error {
 //
 func (g *LightningTerminal) startMainWebServer() error {
 	// Initialize the in-memory file server from the content compiled by
-	// the statik library.
-	statikFS, err := fs.New()
+	// the go:embed directive. Since everything's relative to the root dir,
+	// we need to create an FS of the sub directory app/build.
+	buildDir, err := fs.Sub(appBuildFS, appFilesDir)
 	if err != nil {
-		return fmt.Errorf("could not load statik file system: %v", err)
+		return err
 	}
-	staticFileServer := http.FileServer(&ClientRouteWrapper{statikFS})
+	staticFileServer := http.FileServer(&ClientRouteWrapper{
+		assets: http.FS(buildDir),
+	})
 
 	// Both gRPC (web) and static file requests will come into through the
 	// main UI HTTP server. We use this simple switching handler to send the